Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 19713-19721 |
| Seitenumfang | 9 |
| Fachzeitschrift | Physical Chemistry Chemical Physics |
| Jahrgang | 18 |
| Ausgabenummer | 29 |
| Publikationsstatus | Veröffentlicht - 22 Juni 2016 |
Abstract
Catalytic oxidation of ammonia and CO has been studied in the 10-4 mbar range using a catalyst prepared by depositing ultra-thin vanadium oxide layers on Rh(111) (θV ≈ 0.2 MLE). Using photoemission electron microscopy (PEEM) as a spatially resolving method, we observe that upon heating in an atmosphere of NH3 and O2 the spatial homogeneity of the VOx layer is removed at 800 K and a pattern consisting of macroscopic stripes develops; at elevated temperatures this pattern transforms into a pattern of circular VOx islands. Under reaction conditions the neighboring VOx islands become attracted by each other and coalesce. Similar processes of pattern formation and island coalescence are observed in catalytic CO oxidation. Reoxidation of the reduced VOx catalyst proceeds via surface diffusion of oxygen adsorbed onto Rh(111). A pattern consisting of macroscopic circular VOx islands can also be obtained by heating a Rh(111)/VOx catalyst in pure O2.
ASJC Scopus Sachgebiete
- Physik und Astronomie (insg.)
- Allgemeine Physik und Astronomie
- Chemie (insg.)
- Physikalische und Theoretische Chemie
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in: Physical Chemistry Chemical Physics, Jahrgang 18, Nr. 29, 22.06.2016, S. 19713-19721.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Dynamics of ultrathin V-oxide layers on Rh(111) in catalytic oxidation of ammonia and CO
AU - Von Boehn, B.
AU - Preiss, A.
AU - Imbihl, R.
PY - 2016/6/22
Y1 - 2016/6/22
N2 - Catalytic oxidation of ammonia and CO has been studied in the 10-4 mbar range using a catalyst prepared by depositing ultra-thin vanadium oxide layers on Rh(111) (θV ≈ 0.2 MLE). Using photoemission electron microscopy (PEEM) as a spatially resolving method, we observe that upon heating in an atmosphere of NH3 and O2 the spatial homogeneity of the VOx layer is removed at 800 K and a pattern consisting of macroscopic stripes develops; at elevated temperatures this pattern transforms into a pattern of circular VOx islands. Under reaction conditions the neighboring VOx islands become attracted by each other and coalesce. Similar processes of pattern formation and island coalescence are observed in catalytic CO oxidation. Reoxidation of the reduced VOx catalyst proceeds via surface diffusion of oxygen adsorbed onto Rh(111). A pattern consisting of macroscopic circular VOx islands can also be obtained by heating a Rh(111)/VOx catalyst in pure O2.
AB - Catalytic oxidation of ammonia and CO has been studied in the 10-4 mbar range using a catalyst prepared by depositing ultra-thin vanadium oxide layers on Rh(111) (θV ≈ 0.2 MLE). Using photoemission electron microscopy (PEEM) as a spatially resolving method, we observe that upon heating in an atmosphere of NH3 and O2 the spatial homogeneity of the VOx layer is removed at 800 K and a pattern consisting of macroscopic stripes develops; at elevated temperatures this pattern transforms into a pattern of circular VOx islands. Under reaction conditions the neighboring VOx islands become attracted by each other and coalesce. Similar processes of pattern formation and island coalescence are observed in catalytic CO oxidation. Reoxidation of the reduced VOx catalyst proceeds via surface diffusion of oxygen adsorbed onto Rh(111). A pattern consisting of macroscopic circular VOx islands can also be obtained by heating a Rh(111)/VOx catalyst in pure O2.
UR - http://www.scopus.com/inward/record.url?scp=84979518999&partnerID=8YFLogxK
U2 - 10.1039/c6cp03637f
DO - 10.1039/c6cp03637f
M3 - Article
AN - SCOPUS:84979518999
VL - 18
SP - 19713
EP - 19721
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 29
ER -